#include <stdio.h>
#include <signal.h>
int main(int argc, char **argv)
{
	int m;
	sigset_t set;
	sigemptyset (&set);
	//将二号信号增加到集合中
	sigaddset (&set, 2);
	 m = sigismember (&set, 2);
	if (-1 == m){
		perror("sigismember ()");
	}
	if (1 == m){
		printf ("yes......\n");
	}else if (0 == m){
		printf ("no......\n");
	}
	sigemptyset (&set);
	//将二号信号增加到集合中
	sigdelset (&set, 2);
	 m = sigismember (&set, 2);
	if (-1 == m){
		perror("sigismember ()");
	}
	if (1 == m){
		printf ("yes......\n");
	}else if (0 == m){
		printf ("no......\n");
	}
	return 0;
}
